What are the challenges in combating emerging and reemerging diseases?
Read the section ‘Emerging Diseases’ in your book (Ch1, Microbiology by Tortora) and discuss the following in one or two paragraphs:
Prompts:
What are the challenges in combating emerging and reemerging diseases?
Discuss some of the examples given your book
Some steps we can take to prevent an outbreak of these diseases.
After you read through the chapter, write a short report (in your own words) responding the three prompts above and post to the rest of the class
Microbiology an Introduction
Twelfth Edition
Chapter 1
The Microbial World and You
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
1
Staphylococcus Aureus Bacteria
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes in Our Lives (1 of 4)
Learning Objective
1-1 List several ways in which microbes affect our lives.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes in Our Lives (2 of 4)
Microorganisms are organisms that are too small to be seen with the unaided eye
Microbes include bacteria, fungi, protozoa, microscopic algae, and viruses
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes in Our Lives (3 of 4)
A few are pathogenic (disease-producing)
Decompose organic waste
Generate oxygen by photosynthesis
Produce chemical products such as ethanol, acetone, and vitamins
Produce fermented foods such as vinegar, cheese, and bread
Produce products used in manufacturing (e.g., cellulase) and disease treatment (e.g., insulin)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Designer Jeans: Made by Microbes?
Denim fading: Trichoderma
Cotton production: Gluconacetobacter
Bleaching: mushroom peroxidase
Indigo: Escherichia coli
Plastic: bacterial polyhydroxyalkanoate
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Applications of Microbiology 1.1
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Applications of Microbiology 1.2
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes in Our Lives (4 of 4)
Knowledge of microorganisms allows humans to
Prevent food spoilage
Prevent disease
Understand causes and transmission of disease to prevent epidemics
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-1
Check Your Understanding
Describe some of the destructive and beneficial actions of microbes. 1-1
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Naming and Classifying Microorganisms (1 of 2)
Learning Objectives
1-2 Recognize the system of scientific nomenclature that uses two names: a genus and a specific epithet.
1-3 Differentiate the major characteristics of each group of microorganisms.
1-4 List the three domains.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Naming and Classifying Microorganisms (2 of 2)
Carolus Linnaeus established the system of scientific nomenclature in 1735
Each organism has two names: the genus and the specific epithet
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Nomenclature (1 of 4)
Scientific names
Are italicized or underlined
The genus is capitalized; the specific epithet is lowercase
Are “Latinized” and used worldwide
May be descriptive or honor a scientist
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Nomenclature (2 of 4)
Escherichia coli
Honors the discoverer, Theodor Escherich
Describes the bacterium’s habitat—the large intestine, or colon
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Nomenclature (3 of 4)
Staphylococcus aureus
Describes the clustered (staphylo-) spherical (coccus) cells
Describes the gold-colored (aureus) colonies
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Nomenclature (4 of 4)
After the first use, scientific names may be abbreviated with the first letter of the genus and the specific epithet:
Escherichia coli and Staphylococcus aureus are found in the human body
E. coli is found in the large intestine, and S. aureus is on skin
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-2
Check Your Understanding
Distinguish a genus from a specific epithet. 1-2
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Types of Microorganisms
Bacteria
Archaea
Fungi
Protozoa
Algae
Viruses
Multicellular Animal Parasites
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1 Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Bacteria
Prokaryotes
”Prenucleus”
Single-celled
Peptidoglycan cell walls
Divide via binary fission
Derive nutrition from organic or inorganic chemicals or photosynthesis
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1a Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Archaea
Prokaryotes
Lack peptidoglycan cell walls
Often live in extreme environments
Include:
Methanogens
Extreme halophiles
Extreme thermophiles
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Fungi
Eukaryotes
Distinct nucleus
Chitin cell walls
Absorb organic chemicals for energy
Yeasts are unicellular
Molds and mushrooms are multicellular
Molds consist of masses of mycelia, which are composed of filaments called hyphae
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1b Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Protozoa
Eukaryotes
Absorb or ingest organic chemicals
May be motile via pseudopods, cilia, or flagella
Free-living or parasitic (derive nutrients from a living host)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1c Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Algae
Eukaryotes
Cellulose cell walls
Found in freshwater, saltwater, and soil
Use photosynthesis for energy
Produce oxygen and carbohydrates
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1d Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Viruses
Acellular
Consist of DNA or RNA core
Core is surrounded by a protein coat
Coat may be enclosed in a lipid envelope
Are replicated only when they are in a living host cell
Inert outside living hosts
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.1e Types of Microorganisms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Multicellular Animal Parasites
Eukaryotes
Multicellular animals
Not strictly microorganisms
Parasitic flatworms and roundworms are called helminths
Some microscopic stages in their life cycles
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-3
Check Your Understanding
Which groups of microbes are prokaryotes? Which are eukaryotes? 1-3
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Classification of Microorganisms
Developed by Carl Woese
Three domains based on cellular organization
Bacteria
Archaea
Eukarya
Protists
Fungi
Plants
Animals
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 10.1 Three-Domain System
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-4
Check Your Understanding
What are the three domains? 1-4
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
A Brief History of Microbiology (1 of 2)
Learning Objectives
1-5 Explain the importance of observations made by Hooke and van Leeuwenhoek.
1-6 Compare spontaneous generation and biogenesis.
1-7 Identify the contributions to microbiology made by Needham, Spallanzani, Virchow, and Pasteur.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The First Observations
1665: Robert Hooke reported that living things are composed of little boxes, or “cells”
Marked the beginning of cell theory: All living things are composed of cells
The first microbes were observed from 1623–1673 by Anton van Leeuwenhoek
“Animalcules” viewed through magnifying lenses
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.2b Anton Van Leeuwenhoek’s Microscopic Observations
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-5
Check Your Understanding
What is the cell theory? 1-5
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Debate over Spontaneous Generation (1 of 4)
Spontaneous generation: the hypothesis that life arises from nonliving matter; a “vital force” is necessary for life
Biogenesis: the hypothesis that living cells arise only from preexisting living cells
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Debate over Spontaneous Generation (2 of 4)
1668: Francesco Redi filled jars with decaying meat
| Conditions | Results |
| Jars covered with fine net | No maggots |
| Open jars | Maggots appeared |
| Sealed jars | No maggots |
From where did the maggots come?
What was the purpose of the sealed jars?
Spontaneous generation or biogenesis?
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Debate over Spontaneous Generation (3 of 4)
1745: John Needham put boiled nutrient broth into covered flasks
| Conditions | Results |
| Nutrient broth heated, then placed in covered flask | Microbial growth |
From where did the microbes come?
Spontaneous generation or biogenesis?
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Debate over Spontaneous Generation (4 of 4)
1765: Lazzaro Spallanzani boiled nutrient solutions in sealed flasks
| Conditions | Results |
| Nutrient broth placed in flask, sealed, then heated | No microbial growth |
Spontaneous generation or biogenesis?
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Theory of Biogenesis (1 of 3)
1858: Rudolf Virchow said cells arise from preexisting cells
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Theory of Biogenesis (2 of 3)
1861: Louis Pasteur demonstrated that microorganisms are present in the air
| Conditions | Results |
| Nutrient broth placed in flask, heated, NOT sealed | Microbial growth |
| Nutrient broth placed in flask, heated, then immediately sealed | No microbial growth |
Spontaneous generation or biogenesis?
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Theory of Biogenesis (3 of 3)
Pasteur also used S-shaped flasks
Keep microbes out but let air in
Broth in flasks showed no signs of life
Neck of flask traps microbes
Microorganisms originate in air or fluids, not mystical forces
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.3 Disproving the Theory of Spontaneous Generation
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-6
Check Your Understanding
What evidence supported spontaneous generation? 1-6
How was spontaneous generation disproved? 1-7
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
A Brief History of Microbiology (2 of 2)
Learning Objectives
1-8 Explain how Pasteur’s work influenced Lister and Koch.
1-9 Identify the importance of Koch’s postulates.
1-10 Identify the importance of Jenner’s work.
1-11 Identify the contributions to microbiology made by Ehrlich and Fleming.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Golden Age of Microbiology (1 of 3)
1857–1914
Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Golden Age of Microbiology (2 of 3)
Pasteur showed that microbes are responsible for fermentation
Fermentation is the microbial conversion of sugar to alcohol in the absence of air
Microbial growth is also responsible for spoilage of food and beverages
Bacteria that use air spoil wine by turning it to vinegar (acetic acid)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Golden Age of Microbiology (3 of 3)
Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine
Pasteurization is the application of a high heat for a short time to kill harmful bacteria in beverages
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.4 Milestones in the Golden Age of Microbiology (1 of 3)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Germ Theory of Disease (1 of 3)
1835: Agostino Bassi showed that a silkworm disease was caused by a fungus
1865: Pasteur showed that another silkworm disease was caused by a protozoan
1840s: Ignaz Semmelweis advocated handwashing to prevent transmission of puerperal fever from one obstetrical patient to another
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Germ Theory of Disease (2 of 3)
1860s: Applying Pasteur’s work showing that microbes are in the air, can spoil food, and cause animal diseases, Joseph Lister used a chemical antiseptic (phenol) to prevent surgical wound infections
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.4 Milestones in the Golden Age of Microbiology (2 of 3)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Germ Theory of Disease (3 of 3)
1876: Robert Koch discovered that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, to demonstrate that a specific microbe causes a specific disease
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.4 Milestones in the Golden Age of Microbiology (3 of 3)
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Vaccination
1796: Edward Jenner inoculated a person with cowpox virus, who was then immune from smallpox
Vaccination is derived from the Latin word vacca, meaning cow
The protection is called immunity
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-7
Check Your Understanding
Summarize in your own words the germ theory of disease. 1-8
What is the importance of Koch’s postulates? 1-9
What is the significance of Jenner’s discovery? 1-10
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The Birth of Modern Chemotherapy: Dreams of a “Magic Bullet”
Treatment of disease with chemicals is called chemotherapy
Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics
Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
The First Synthetic Drugs
Quinine from tree bark was long used to treat malaria
Paul Ehrlich speculated about a “magic bullet” that could destroy a pathogen without harming the host
1910: Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis
1930s: Sulfonamides were synthesized
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
A Fortunate Accident—Antibiotics
1928: Alexander Fleming discovered the first antibiotic (by accident)
Fleming observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus
1940s: Penicillin was tested clinically and mass-produced
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.5 The Discovery of Penicillin
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-8
Check Your Understanding
What was Ehrlich’s “magic bullet”? 1-11
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Modern Developments in Microbiology
Learning Objectives
1-12 Define bacteriology, mycology, parasitology, immunology, and virology.
1-13 Explain the importance of microbial genetics and molecular biology.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Bacteriology, Mycology, and Parasitology
Bacteriology is the study of bacteria
Mycology is the study of fungi
Parasitology is the study of protozoa and parasitic worms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.6 Parasitology: The Study of Protozoa and Parasitic Worms
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Immunology
Immunology is the study of immunity
Vaccines and interferons are used to prevent and cure viral diseases
A major advance in immunology occurred in 1933 when Rebecca Lancefield classified streptococci based on their cell wall components
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.7 Rebecca Lancefield (1895–1981)
Rebecca Lancefield (1895–1981), who discovered differences in the chemical composition of a polysaccharide in the cell walls of many pathogenic streptococci.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Virology
Virology is the study of viruses
Dmitri Iwanowski in 1892 and Wendell Stanley in 1935 discovered the cause of mosaic disease of tobacco as a virus
Electron microscopes have made it possible to study the structure of viruses in detail
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Recombinant DNA Technology (1 of 2)
Microbial genetics: the study of how microbes inherit traits
Molecular biology: the study of how DNA directs protein synthesis
Genomics: the study of an organism’s genes; has provided new tools for classifying microorganisms
Recombinant DNA: DNA made from two different sources
In the 1960s, Paul Berg inserted animal DNA into bacterial DNA, and the bacteria produced an animal protein
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Recombinant DNA Technology (2 of 2)
1941: George Beadle and Edward Tatum showed that genes encode a cell’s enzymes
1944: Oswald Avery, Colin MacLeod, and Maclyn McCarty showed that DNA is the hereditary material
1953: James Watson and Francis Crick proposed a model of DNA structure
1961: François Jacob and Jacques Monod discovered the role of mRNA in protein synthesis
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.4 Milestones in the Golden Age of Microbiology
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-9
Check Your Understanding
Define bacteriology, mycology, parasitology, immunology, and virology. 1-12
Differentiate microbial genetics from molecular biology. 1-13
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes and Human Welfare
Learning Objectives
1-14 List at least four beneficial activities of microorganisms.
1-15 Name two examples of biotechnology that use recombinant DNA technology and two examples that do not.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Recycling Vital Elements
Microbial ecology is the study of the relationship between microorganisms and their environment
Bacteria convert carbon, oxygen, nitrogen, sulfur, and phosphorus into forms used by plants and animals
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Bioremediation: Using Microbes to Clean Up Pollutants
Bacteria degrade organic matter in sewage
Bacteria degrade or detoxify pollutants such as oil and mercury
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 27.8 Composting Municipal Wastes
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Insect Pest Control by Microorganisms
Microbes that are pathogenic to insects are alternatives to chemical pesticides
Prevent insect damage to agricultural crops and disease transmission
Bacillus thuringiensis infections are fatal in many insects but harmless to animals and plants
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 11.21 Bacillus
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Modern Biotechnology and Recombinant DNA Technology
Biotechnology is the use of microbes for practical applications, such as producing foods and chemicals
Recombinant DNA technology enables bacteria and fungi to produce a variety of proteins, vaccines, and enzymes
Missing or defective genes in human cells can be replaced in gene therapy
Genetically modified bacteria are used to protect crops from insects and from freezing
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-10
Check Your Understanding
Name two beneficial uses of bacteria. 1-14
Differentiate biotechnology from recombinant DNA technology. 1-15
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Microbes and Human Disease
Learning Objectives
1-16 Define normal microbiota and resistance.
1-17 Define biofilm.
1-18 Define emerging infectious disease.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Normal Microbiota (1 of 2)
Bacteria were once classified as plants, giving rise to the term flora for microbes
This term has been replaced by microbiota
Microbes normally present in and on the human body are called normal microbiota
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.8 Several Types of Bacteria
Several types of bacteria found as part of the normal microbiota on the surface of the human tongue.
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Normal Microbiota (2 of 2)
Normal microbiota prevent growth of pathogens
Normal microbiota produce growth factors such as vitamins B and K
Resistance is the ability of the body to ward off disease
Resistance factors include skin, stomach acid, and antimicrobial chemicals
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Biofilms
Microbes attach to solid surfaces and grow into masses
They will grow on rocks, pipes, teeth, and medical implants
Biofilms can cause infections and are often resistant to antibiotics
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 1.9 Biofilm on a Catheter
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (1 of 3)
When a pathogen invades a host and overcomes the host’s resistance, disease results
Emerging infectious diseases (EIDs): new diseases and diseases increasing in incidence
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (2 of 3)
Middle East respiratory syndrome (MERS)
Caused by Middle East respiratory syndrome coronavirus (MERS-CoV)
Common to SARS
Severe acute respiratory syndrome
100 deaths in the Middle East from 2012 to 2014
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (3 of 3)
Avian influenza A (H5N1)
Influenza A virus
Primarily in waterfowl and poultry
Sustained human-to-human transmission has not yet occurred
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 13.3b Morphology of an Enveloped Helical Virus
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (1 of 7)
Methicillin-resistant Staphylococcus aureus (MRSA)
1950s: Penicillin resistance developed
1980s: Methicillin resistance
1990s: MRSA resistance to vancomycin reported
VISA: vancomycin-intermediate S. aureus
VRSA: vancomycin-resistant S. aureus
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (2 of 7)
West Nile encephalitis (WNE)
Caused by West Nile virus
First diagnosed in the West Nile region of Uganda in 1937
Appeared in New York City in 1999
In nonmigratory birds in 48 states
Transmitted between birds and to horses and humans by mosquitoes
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Diseases in Focus 22.2
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (3 of 7)
Bovine spongiform encephalopathy
Caused by a prion
An infectious protein that also causes Creutzfeldt-Jakob disease (CJD)
New variant of CJD in humans is related to cattle that have been given feed made from prion-infected sheep
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 22.18b Spongiform Encephalopathies
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (4 of 7)
E. coli O157:H7
Toxin-producing strain of E. coli
First seen in 1982; causes bloody diarrhea
Leading cause of diarrhea worldwide
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 25.11 Pedestal formation by Enterohemorrhagic E. coli (EHEC) O157:H7
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (5 of 7)
Ebola hemorrhagic fever (EHF)
Ebola virus
Causes fever, hemorrhaging, and blood clotting
Transmitted via contact with infected blood or body fluids
First identified near Ebola River, Congo
2014 outbreak in Guinea; hundreds killed
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 23.21 Ebola Hemorrhagic Virus
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (6 of 7)
Cryptosporidiosis
Cryptosporidium protozoa
First reported in 1976
Causes 30% of diarrheal illness in developing countries
In the United States, transmitted via water
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Figure 25.17 Cryptosporidiosis
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Emerging Infectious Diseases (7 of 7)
AIDS (acquired immunodeficiency syndrome)
Caused by human immunodeficiency virus (HIV)
First identified in 1981
Sexually transmitted infection affecting males and females
Worldwide epidemic infecting 35 million people; 6000 new infections every day
HIV/AIDS in the United States: 26% are female, and 49% are African American
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
Check Your Understanding-11
Check Your Understanding
Differentiate normal microbiota and infectious disease. 1-16
Why are biofilms important? 1-17
What factors contribute to the emergence of an infectious disease? 1-18
Copyright © 2016 Pearson Education, Inc. All Rights Reserved
